Adjustable leveling implement for finishing cast concrete layers



Aug. 1, 1967 H. WOLF 7 3,333,380

ADJUSTABLE LEVELING IMPLEMENT FOR FINISHING CAST CONCRETE LAYERS Filed Jan. 28, 1965 2 Sheets-Sheet 1 I N V EN TOR. #467465 WOLF BY d h e/ yJ ADJUSTABLE LEVELING IMPLEMENT FOR FINISHING.

CAST CONGRETE'LAYERS Filed Jan. 28, 1 965 2 Sheets-Sheet 2 Fig.4

INVENTOR. h'lfll. WOLF ATTOIQA/EKS' United States Patent 6 Claims. (Cl. 52-365) The present invention relates to an implement for finishing freshly cast layers of concrete and especially reinforced concrete, by leveling and smoothing the same.

According to the conventional procedure of finishing freshly cast concrete layers it is customary before the concrete is poured into its wooden form to erect a pair of finishing stands at both sides of the subsequent concrete layer and in such a position that their horizontal upper edges extend substantially parallel to and at a suitable distance from each other. After the concrete is poured and distributed in the form, a finishing board with a straight edge is layed across the two finishing stands and moved back and forth along them so as to scrape off the excess concrete and at the same time to level and smooth its surface.

The most simple type of such finishing stands consist of a pair of long boards which have a width equal to the desired thickness of the concrete layer and are placed with their narrow longitudinal edge portions upon the bottom of the concrete form. Such boards must be specially selected or finished in each case so that their width is exactly in accordance with the desired concrete layer thickness and very frequently they can be mounted only with considerable difficulties between the reinforcing bars which are inserted into the form. It is another serious disadvantage of these boards serving as finishing stands that, after the leveling operation has been completed, they can be removed from the concrete only with great difliculties.

Another known type of finishing stands consist of long wooden benches each of which has two feet for mounting it on the bottom of the concrete form. Such a bench generally consists of a narrow board, the wider side of which extends parallel to the surface of the concrete layer, and at least a pair of feet on the lower side of this board and of a width substantially equal to that of the board. By exchanging the feet or cutting them off to the proper size, such a bench may be adjusted so as to be in accordance with the desired thickness of the concrete layer, and usually such a finishing bench may be more easily mounted in the concrete form between the reinforcing bars thereof than a simple finishing board of the first-mentioned type which is placed directly with its narrow longitudinal edge portion on the bottom of the concrete form. However, even these benchlike finishing stands can only be removed with difiiculties from the leveled and finished concrete layer, and they have the further disad- Vantage that the troughlike depression which is formed in the concrete surface by the finishing board must be subsequently filled out with concrete by hand.

It is an object of the present invention to provide an implement which is universally applicable for leveling and smoothing concrete layers, is easily adjustable to any level in accordance with the desired thickness of the concrete layer, may be mounted without difficulties in the concrete form between the reinforcing bars, and may be easily removed after the finishing operation has been completed.

According to the invention, this object is attained by providing a finishing stand which consists of a long leveling bar on which two posts are secured which consist of tubular sleeves of a certain length which are secured to the leveling bar near the ends thereof and extend substantially parallel to each other in the same direction from the leveling bar, and of a supporting rod which is telescopically slidable within and projects from the free end of each sleeve and is adapted to be locked thereto in different positions and provided on its outer end with anchoring means. When the finishing stand according to the invention is to be employed, the supporting rods are shifted within the sleeves until the distance between the upper edge of the leveling bar and the contact surfaces between the anchoring means and the ends of the supporting rods corresponds to the thickness of the desired concrete layer, whereupon the rods are locked to the sleeves on the leveling bar. After two such finishing stands have been adjusted to the same height, they are placed parallel to and at a certain distance from each other on the bottom of the concrete form so that their posts consisting of the sleeves and supporting rods extend vertic-ally thereto, and they are then anchored in a fixed position by driving the anchoring means, for example, simple spikes on the lower ends of the supporting rods, to a certain depth into the bottom boards of the concrete form, for example, up to the upper ends of the spikes. After the concrete layer has been leveled and smoothed in the usual manner by drawing a finishing board along the leveling bars of the finishing stands, their anchoring means may be loosened without difliculty from the bottom boards of the concrete form and they may then be easily removed from the concrete. The holes which are formed in the concrete by the thin pipe pieces and rods, and the shallow troughlike depression which is formed by the narrow leveling bar are so small that they do not require any finishing operation since the concrete flows into and fills out these parts of its own accord.

According to one preferred embodiment of the invention, the tubular sleeves of each finishing stand are provided with a plurality of diametrically opposite holes at certain distances from each other in the axial direction of each sleeve, and the supporting rods are provided with similar transverse bores. By shifting each supporting rod within the associated sleeve so that one of its bores is in alignment with a pair of corresponding holes in the sleeve and by then inserting [a cotter pin into the aligned holes, it is possible to adjust each finishing stand to the desired height. If, for example, the distance between the adjacent holes in the sleeves amounts to 20 mm. and each supporting rod is provided with two transverse bores at a distance of 10 mm. from each other, it is possible to adjust the height of the finishing stands within a certain range from one centimeter to another.

At its points of connection to the ends of the sleeves, each leveling bar may be provided with apertures which are coaxial with the sleeves and have a diameter equal to the inner diameter of these sleeves. This permits the supporting rods to be inserted into the sleeves in such a manner that the anchoring means thereon point in the direction away from the sleeves. Therefore, when the finishing stand is turned approximately about the longitudinal axis of its leveling bar, the latter may be adjusted relative to its supporting rods to a very low height for leveling very thin concrete layers. Such a leveling operation is then carried out by means of the lower edge of the leveling bar.

According to another feature of the invention, the

leveling bar of each finishing stand is preferably provided along its entire length and along its longitudinal axis or along a line parallel thereto with small holes through which, if desired, nails may be inserted for nailing thin upright boards on the finishing stand for forming expansion joints in the concrete layer.

If the finishing stand has a very great length, the leveling bar thereof may be provided at its longitudinal center or at points symmetrical thereto with one or more additional posts consisting of sleeves and associated supporting rods as described.

According to another feature of the invention, the sleeves of a finishing stand may be secured to the leveling bar so as not to extend parallel but at a slight inclination to each other so that their axes diverge at an acute angle symmetrically to the vertical longitudinal central plane of the leveling bar. This has the advantage that the finishing stand may be more steadily mounted.

The leveling bar of each finishing stand has preferably an L, U, I, or Z-shaped cross section and consists of rolled steel. Such roll-steel bars are highly resistant to bending and are therefore especially suitable for finishing stands of a considerable length. It is, however, also possible to make the leveling bar of hard plastic in order to reduce its cost. In this case, the sleeve members may also be made of plastic and the leveling bar and the sleeve members may be made integrally with each other of one piece of material.

The anchoring means for the supporting rods preferably consist of simple spikes which are secured to the outer ends of the rods and are adapted to be driven into the wood of the concrete form. For attaining a better grip in the wood, these spikes may be provided with peripheral grooves. They may preferably also be provided with a threaded stem to permit them to be screwed into a tapped bore in the free end of the supporting rod. Such threaded spikes are easily exchangeable so that spikes which have become bent or dull in use may be quickly exchanged for new spikes.

In old form boards which have been frequently used and may have become somewhat rotten, it is not always sure that a supporting rod which carries only a single spike will be securely anchored. According to a further feature of the invention, the anchoring means for each rod therefore consists of a disk which is provided with a central bore and several equally spaced spikes projecting therefrom. This disk may then be secured to the free end of the supporting rod by a threaded central spike which is screwed into a tapped bore in the end of the rod or by an ordinary headed screw or in any other suitable manner, for example, by welding it to the supporting rod.

For additionally supporting the finishing stand, for example, on a hard base, bracing stands may be provided which may be slipped over the sleeve members on the leveling bar and be secured thereto by the cotter pins. These additional bracing stands when properly adjusted in the vertical direction may be employed together with the supporting rods of the finishing stand for erecting the latter. Each of these bracing stands consists of a pair of legs which extend at an acute angle to each other and are secured at one end to the outside of a piece of pipe which has an inner diameter slightly larger than the outer diameter of the sleeves of the finishing stand and is provided with several pairs of diametrically opposite trans verse holes which have a diameter equal to that of the transverse holes in the sleeves of the finishing stand and extend in a direction at right angles to the common plane of the two legs.

For mounting the finishing stand on a concrete form which consists of sheet iron or steel, the anchoring means on the free ends of the supporting rods of the finishing stand preferably consist of cylindrical permanent magnets of a cross-sectional size equal to that of the rods. Each of these permanent magnets is preferably provided with a threaded stem for screwing it into the tapped bore in the free end of the supporting rod or it may be provided with a conical recess of a shape in accordance with the shape of the spikes on the ends of the supporting rod so as to permit the permanent magnets to be fitted over and clamped to these spikes. A finishing stand according to the invention which is equipped with such permanent magnets on the ends of its supporting rods may be placed upon the bottom of a metallic concrete form, and the magnetic force of the permanent magnets will then be sufficient to maintain the finishing stand in a steady poistion even during the time when the concrete is being poured into its form.

Another feature of the invention consists in the provision of means for preventing the entry of liquid concrete into the holes of the sleeves on the section bar and into the space between these sleeves and the supporting rods therein. These means consist of protecting tubes of an elastic material which have the same length as the sleeve of the finishing stand and may be slipped over and turned around the same. Each of these tubes is provided at one end which corresponds to the free end of one of the sleeves with an annular inwardly projecting flange which is adapted to fit around the supporting rod. The protecting tube is further provided with a plurality of diametrically opposite pairs of holes which have the same width and are spaced from each other at the same distance as the holes in the sleeves, and they are offset about a certain sector angle relative to each adjacent pair. When such a tube is slipped over a sleeve of the finishing stand, possibly by the aid of a lubricant, and the tube is in the proper position, all of the holes in the sleeve may be covered by the tube. By turning this tube on the sleeve, it is then possible to find a position in which one pair of holes of the tube is in alignment with one or another pair of holes of the sleeve, while all other holes of the sleeve are completely covered by the protective tube. A cotter pin is then inserted into the aligned holes in the protecting tube and the sleeve and also through one of the transverse bores in the supporting rod so that the latter is secured in a fixed position relative to the sleeve. The inner flange of the protecting tube which surrounds the supporting rod seals the annular gap between the sleeve and the rod.

These as well as additional features and advantages of the present invention will become more clearly apparent from the following detailed description thereof which is to be read with reference to the accompanying drawings, in which:

FIGURE 1 shows a perspective view of a finishing stand according to the invention with a steel bar of an L-shaped cross section, a part of which is broken away;

FIGURE 2 shows, partly in vertical section, a disk which is provided with several spikes and screwed upon the free end of a supporting rod of the finishing stand;

FIGURE 3 shows a front view of a bracing stand;

FIGURE 4 shows a longitudinal section of a protecting tube which is provided with five pairs of transverse holes which are longitudinally spaced and peripherally offset relative to each other;

FIGURE 5 shows a cross section which is taken along the line V-V of FIGURE 4;

FIGURE 6 shows, partly in longitudinal section, the end of a supporting rod of the finishing stand with a permanent magnet secured thereto; while FIGURE 7 shows, partly in longitudinal section, the spike-tipped end of a supporting rod of the finishing stand with a permanent magnet fitted over the spike.

As illustrated in FIGURE 1 of the drawings, the finishing stand 1 according to the invention consists of a long leveling bar in the form of an angle steel bar 2, one arm of flange of which is provided near its ends with circular holes 3 and with a plurality of smaller holes 4 at suitable distances from each other along its entire length in alignment with the centers of the larger holes 3. The inner side of this flange of leveling bar 2 carries a pair of tubular sleeves 5 of a suitable length which extend vertically to the longitudinal axis of the leveling bar and coaxially to the holes 3 and have an inner diameter equal to that of these holes. The sleeves 5 are provided with a plurality of pairs of diametrically opposite holes 6 which are equally spaced from each other longitudinally of each sleeve 5. These sleeves 5 are adapted to receive cylindrical supporting rods 8 which are slidable therein in the axial direction and adapted to be removed therefrom, and they are provided with transverse bores 7 of the same diameter and the same distance from each other as the holes 6 in the sleeves 5. The free end of each of these supporting rods carries an acute conical spike 9 which is preferably removably secured thereto. The diameter of this spike 9 at its end facing the supporting rod 8 is considerably smaller than the diameter of rod 8 so that an end surface is formed on the end of the supporting rod which, apart from its adjustability, determines the height of the finishing stand. Near the middle of its length spike 9 is provided with an annular groove 10 to exert a better grip in the wood of the concrete form. For securing the supporting bars 8 in a fixed position in the sleeves 5, cotter pins 11 may be inserted into and passed through one of the transverse bores 7 in rods 8 and a pair of opposite holes 6 in the sleeves 5.

FIGURE 2 illustrates a disk 13 which is provided with additional spikes 12 and may be secured to the free end of the supporting rod 8 either by a headed screw or by means of a central spike 15 which has a threaded stem 14 which may be screwed into a tapped bore in the end of rod 8.

FIGURE 3 illustrates an additional bracing stand 16 which has a pair of legs 17 with pointed ends which are secured at an acute angle to each other to the outside of a piece of pipe 18 which has an inner diameter slightly larger than the outer diameter of the sleeves 5 of the finishing stand. This pipe 18 is provided with several pairs of transverse holes 19 diametrically opposite to each other and of a size equal to that of the holes 6 in the sleeves 5. The upper and lower edges of pipe 18 are provided with opposite recesses 20.

FIGURES 4 and 5 show at protecting tube 21 which preferably consists of rubber and has an inner diameter slightly smaller than the outer diameter of the sleeves 5. The lower end of the protecting tube 21 is provided with an inwardly projecting flange 22 which has an inner diameter slightly smaller than the diameter of the supporting rods 8 which are slidable within the sleeves 5. The protecting tube 21 has a certain number of pairs of diametrically opposite holes 23 equal to the number of holes 6 in each sleeve 5 and of a diameter equal to that of the holes 6. These holes 23 are spaced from each other in the axial direction of tube 21 at a distance equal to that between the adjacent holes 6 in each sleeve 5, and each pair of holes 23 is peripherally offset at an angle of 36 relative to the adjacent pairs.

FIGURE 6 shows the free end of a supporting rod 8 which is provided with a tapped bore into which the threaded stem 24 of a cylindrical permanent magnet 28 is screwed which has a diameter equal to that of rod 8.

FIGURE 7 shows the free end of a supporting rod 8 with a conical spike 9 thereon and a cylindrical permanent magnet 25' with a conical recess 26 therein fitted over the spike 9 and removably secured thereto, for example, by a pin, not shown, which extends through a transverse bore in both parts.

The protecting tube 21 according to FIGURES 4 and 5 may be slipped over the sleeves 5 of the finishing stand 1, if necessary by the aid of a lubricant, for example, grease, and they may then be turned on the sleeves 5 so that, in order to prevent the entry of liquid concrete, their holes 23 cover all of the holes 6 in the sleeves 5, except that pair of holes 6 through which the cotter pins 11 are inserted for locking the supporting rods in a fixed position to the sleeves 5. The inner flange 22 at the lower end of a protecting tube 21 is adapted to engage with rod 8 so as to seal the annular gap between the sleeve 5 and the supporting rod 8. The insertion of grease between the protecting tube 21 and the sleeve 5 not only facilitates the operations of slipping the tube 21 over the sleeve and withdrawing it therefrom, but it also serves as an additional sealing means for preventing the entry of moisture between the supporting rod 8 and the sleeve 5.

The permanent magnets 25 or 25' which may be secured to the free ends of the supporting rods 8 permit the finishing stand to be mounted in a fixed position on a concrete form of sheet iron or sheet steel. In such a case, all of the supporting rods 8 ofthe finishing stand 1 are equipped with'permanent magnets 25 or 25 and the finishing stand is mounted in the usual manner on the bottom of the steel form. The magnetic force of the permanent magnets is sufficient to maintain the finishing stand in a steady position while the concrete is being poured.

When the finishing stand 1 is to be used, it is adjusted to the desired thickness of the concrete layer by sliding the supporting rods more or less deeply into the sleeves 5 and by then locking them thereto by means of the cotter pins 11.

For securing the finishing stand 1 on a wooden concrete form, the spikes 9 are driven fully into the form boards so that the lower end surfaces of the supporting stands 8 engage upon the form boards. If the form boards have already been frequently used and are in a poor condition, the spikes 9 may be exchanged on the ends of the supporting rods 8 for the spiked disks 13.

If a finishing stand 1 should be additionally supported on the concrete form, the bracing stands 16 may be employed. The pipe pieces 18 of these bracing stands are then slipped over the sleeves 5 of the finishing stand and locked thereto by the cotter pins 11.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no .way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.

Having thus fully. disclosed my invention, what I claim is:

1. An implement forming a finishing stand for leveling and smoothing freshly cast concrete layers comprising a leveling bar, a pair of tubular sleeves of an equal length secured to one side of said 'bar near the opposite ends thereof and extending vertically to the longitudinal axis of said bar, a pair of supporting rods telescopically slidable within said sleeves and projecting from the free ends thereof, means for locking said supporting rods at different length adjustments to said sleeves and anchoring means secured to the free ends of said rods, each of said sleeves on said leveling bar having a plurality of pairs of diametrically-opposed transverse holes therein spaced from each other in the axial direction of said seleves, said supporting rods having transverse bores spaced from each in the axial direction and having the same diameter as said transverse holes, said locking means comprising at least one cotter pin adapted to be inserted through one of said pairs of holes in each of said sleeves and through one of said bores in each of said rods in axial alignment with said last pair of holes, protecting tubes of elastic material each having a length substantially equal to the length of one of said sleeves on said leveling bar and being slipped over said sleeve and turned thereon and to prevent liquid concrete from entering into the holes in said sleeve and into the space between said sleeve and the associated supporting rod, each of said tubes having an inwardly projecting annular flange at the end thereof located adjacent to the free end of said sleeve. and surrounding and tightly engaging with a part of said supporting rod projecting from the free end of said sleeve, said tube having a plurality of pairs of diametrically opposite holes therein corresponding in number and axial distance from each other to said holes in said sleeve and having a diameter at least not larger than that of said holes in said sleeve, each pair of said holes in said tube being peripherally offset by an equal sector angle relative to the adjacent pairs.

2. Apparatus for leveling and smoothing the surface of concrete articles after the concrete has been poured, comprising: a leveling bar, support means attached to said leveling bar, including means for rendering said support means adjustable in length, anchoring meansatfixed to the lower-most end of said support means, and protecting tubes of elastic material surrounding and tightly engaging with said support means for protecting said means for adjusting length of said support means from contact with liquid concrete, said last means including tubular sleeves, rigidly attached to said leveling bar near the ends thereof and projecting therefrom, supporting rods, telescopically slidable within said sleeves, said sleeves having a plurality of pairs of diametricallyopposed, transverse holes therein, said pairs of holes being spaced from each other in the axial direction of said sleeves, said supporting rods having transverse bores spaced from each other in the axial direction thereof, said transverse bores having substantially the same diameter as said transverse holes in said sleeves, and key means inserted through one pair of said transverse holes and through one of said transverse bores for fixing said sleeve relative to said supporting rod, said protecting tubes being provided with a plurality of pairs of diametricallyopposed, transverse holes, said pairs of holes spaced from each other in the axial direction of said tubes, each of said pairs of holes being angularly offset with respect to the remainder of said pairs of holes.

3. A combination according to claim 2, wherein said protecting tubes have a length substantially equal to the length of said tubular sleeves, said tubes being slipped over said sleeves and being turned thereon, thus preventing concrete from entering into the inner space of said sleeves through said transverse holes therein.

4. A combination according to claim 2, wherein said protecting tubes are provided with an inwardly-extending annular flange at one end thereof, said flange thus surrounding and tightly engaging with 31 portion of said supporting rod projecting from the free end of said sleeve.

5. A combination according to claim 2, wherein at least two additional sleeves are provided, spaced equidistantly from the ends of said leveling bar.

6. A combination according to claim 2, wherein said sleeves project from said leveling bar at equal acute angles with the longitudinal axis of said bar, said sleeves diverging with respect to each other in the direction of their free ends.

References Cited UNITED STATES PATENTS 1,090,545 3/1914 Kneas 52701 1,114,013 10/1914 Millar 52701 1,592,681 7/1926 Grothe 52365 1,710,886 4/ 1929 Meyer 2483 65 1,726,286 8/1929 Bennet 52699 1,755,457 4/1930 OHare 52365 1,852,673 4/1932 Pilj 52678 2,096,062 10/ 1937 Phillips 52699 2,373,284 4/ 1945 Autrey 52678 2,551,826 5/1951 Cox 52678 3,047,931 8/1962 Boettner 25-131 3,255,565 6/1966 Menzel 52678 FOREIGN PATENTS 374,536 6/ 1932 Great Britain.

815,384 6/1959 Great Britain.

254,176 12/1948 Switzerland.

FRANK L. ABBOTT, Primary Examiner.

A. C. PERI-1AM, Assistant Examiner. 

1. AN IMPLEMENT FORMING A FINISHING STAND FOR LEVELING AND SMOOTHING FRESHLY CAST CONCRETE LAYERS COMPRISING A LEVELING BAR, A PAIR OF TUBULAR SLEEVES OF AN EQUAL LENGTH SECURED TO ONE SIDE OF SAID BAR NEAR THE OPPOSITE ENDS THEREOF AND EXTENDING VERTICALLY TO THE LONGITUDINAL AXIS OF SAID BAR, A PAIR OF SUPPORTING RODS TELESCOPICALLY SLIDABLE WITH SAID SLEEVES AND PROJECTING FROM THE FREE ENDS THEREOF, MEANS FOR LOCKING SAID SUPPORTING RODS AT DIFFERENT LENGTH ADJUSTMENTS TO SAID SLEEVES AND ANCHORING MEANS SECURED TO THE FREE ENDS OF SAID RODS, EACH OF SAID SLEEVES ON SAID LEVELING BAR HAVING A PLURALITY OF PAIRS OF DIAMETRICALLY-OPPOSED TRANSVERSE HOLES THEREIN SPACED FROM EACH OTHER IN THE AXIAL DIRECTION OF SAID SLEEVES SAID SUPPORTING RODS HAVING TRANSVERSE BORES SPACED FROM EACH IN THE AXIAL DIRECTION AND HAVING THE SAME DIAMETER AS SAID TRANSVESE HOLES, SAID LOCKING MEANS COMPRISING AT LEAST ONE COTTER PIN ADAPTED TO BE INSERTED THROUGH ONE OF SAID PAIRS OF HOLES IN EACH OF SAID SLEEVES AND THROUGH ONE OF SAID PAIRS OF HOLES IN EACH OF SAID RODS IN AXIAL ALIGNMENT WITH SAID LAST PAIR OF HOLES, PROTECTING TUBES OF ELASTIC MATERIAL EACH HAVING A LENGTH SUBSTANTIALLY EQUAL TO THE LENGTH OF ONE OF SAID SLEEVES AND TURNED LEVELING BAR AND BEING SLIPPED OVER SAID SLEEVE AND TURNED THEREON AND TO PREVENT LIQUID CONCRETE FROM ENTERING INTO THE HOLES IN SAID SLEEVE AND INTO THE SPACE BETWEEN SAID SLEEVE AND THE ASSOCIATED SUPPORTING ROD, EACH OF SAID TUBES HAVING AN INWARDLY PROJECTING ANNULAR FLANGE AT THE END THEREOF LOCATED ADJACENT TO THE FREE END OF SAID SLEEVE AND SURROUNDING AND TIGHTLY ENGAGING WITH A PART OF SAID SUPPORTING ROD PROJECTING FROM THE FREE END OF SAID SLEEVE, SAID TUBE HAVING A PLURALITY OF PAIRS OF DIAMETRICALLY OPPOSITE HOLES THEREIN CORRESPONDING IN NUMBER AND AXIAL DISTANCE FROM EACH OTHER TO SAID HOLES IN SAID SLEEVE AND HAVING A DIAMETER AT LEAST NOT LARGER THAN THAT OF SAID HOLES IN SAID SLEEVE, EACH PAIR OF SAID HOLES IN SAID TUBE BEING PERIPHERALLY OFFSET BY AN EQUAL SECTOR ANGLE RELATIVE TO THE ADJACENT PAIRS. 